Effect of different agroecosystem management on community structure of insects in soybean crop in Ngale, Ngawi District, East Java. Insect community structures in agroecosystem may always change. Agroecosystem management techniques affect insect community structure. The aim of this study was to determine the diversity and composition of insects on soybean plants under different pest management systems and varieties. The experiment design was split plot with varieties (Anjasmoro and Wilis) as the main plots and pest management systems (Integrated Pest Management (IPM), Non-Chemical Management (P-NK), Chemical Management (P-K), and Control) as the sub plots. There were ten insect sampling sessions for each plot. Samplings were done in June until September 2013 using pitfall traps, sticky traps, sweep net, and yellow pan traps. Statistically the results of experiment showed that varieties and pest management had no significant differences to the insects diversity. Herbivore and beneficial insect in soybean crop had differences composition between varieties Anjasmoro and Wilis. In both soybean Anjasmoro and Wilis varieties, herbivore populations tend to be higher in the control plots compared to the IPM plots. Abundance of decomposers, parasitoids, and predators tend to be higher in the control and P-NK plots which were without the use of synthetic insecticides compared to the IPM and P-K plots which were given the treatment of synthetic pesticides. This indicates that the use of pesticides causes decrease in the beneficial insect populations such as pollinator, parasitoids, and predators.Key words: Anjasmoro variety, insect diversity, insect pests, parasitoids, population dynamics, predators, Wilis variety ABSTRAK Pengaruh perbedaan pengelolaan agroekosistem tanaman terhadap struktur komunitas serangga pada pertanaman kedelai di Ngale, Kabupaten Ngawi, Jawa Timur. Struktur komunitas serangga di agroekosistem selalu berubah. Pengelolaan agroekosistem pertanian mempengaruhi struktur komunitas serangga. Penelitian ini bertujuan untuk men getahui keanekaragaman dan komposisi serangga pada tanaman kedelai dengan pengelolaan hama dan varietas yang berbeda. Rancangan percobaan yang digunakan adalah rancangan petak terbagi RAK dengan petak utama varietas (Anjasmoro dan Wilis) dan pengelolaan hama sebagai anak petak. Pengelolaan hama meliputi Pengelolaan Hama Terpadu (PHT), Pengendalian Non-Kimiawi (P-NK), Pengendalian Kimiawi (P-K), dan Kontrol. Terdapat sepuluh kali sampling serangga pada masingmasing petak dalam satu musim tanam. Pengambilan sampel serangga pada bulan Juni sampai September 2013 dengan menggunakan perangkap lubang jebakan, jaring serangga, perangkap nampan kuning, dan perangkap berperekat. Hasil penelitian menunjukkan bahwa perlakuan varietas dan pengelolaan hama tidak berpengaruh signifikan terhadap indeks keanekaragaman serangga. Komposisi serangga herbivora dan serangga bermanfaat di pertanaman kedelai memiliki perbedaan komposisi spesies antara varietas Anjasmoro dan Wilis. Pada kedua varietas...

The presence of new pest Spodoptera frugperda J. E. Smith has the potential to reduce corn production, so its existence needs to be controlled. The aim of this research is to obtain control techniques that could reduce the intensity of S. frugiperda pest’s attack. The research was conducted from June to October 2020. The experiment was designed in a randomized block design (RBD) with 9 replications and 3 treatments consisting of non-control (NP), PHT-biointensive (BI), and synthetic pesticides. In BI treatment, neem leaf extract (25 mL/plot) and Beauveria bassiana (6,25 g/plot) were used. Meanwhile, the PS treatment used deltametrin active ingredient (3,125 mL/plot). The volume of spray used was 1,25 L. The results showed that PS control techniques gave the best results in suppressing the intensity of fall armyworm S. frugiperda attacks (0,57%-7,04%) followed by BI treatment (0%-6,89%) and NP (0,97%-8,29%). The highest pest populations overall were found in NP treatment and the lowest in PS treatment. PS treatment provided the highest production result with a cob weight of 18,6 kg/plot (24,81 tons/ha), while BI treatment of 17,00 kg/plot (22,72 tons/ha) and NP of 15,44 kg/plot (20,64 tons/ha). The results of the correlation test between the intensity of pest attacks and production results showed that the higher the pest attack, the lower the harvest weight produced. Therefore, pest control by using synthetic pesticides made from active deltametrin is declared effective in suppressing the intensity of attacks and populations of fall armyworm S. frugiperda and able to provide high production results.   Keywords: corn, intensity of attack, Spodoptera frugiperda

Kutukebul Bemisia tabaci (Gennadius) biotipe B yang juga dikenal sebagai Bemisia argentifolii  (Gennadius) merupakan jenis biotipe yang lebih ganas dalam merusak tanaman dibandingkan dengan biotipe non-B. Saat ini kutukebul B. tabaci biotipe B telah dilaporkan keberadaanya di Indonesia. Informasi dasar, seperti siklus hidup, lama hidup, keperidian, dan kemampuan berkembang biak kutukebul sangat diperlukan sebagai dasar dalam menyusun strategi pengendalian hama kutukebul tersebut. Penelitian bertujuan untuk mempelajari siklus hidup dan statistik demografi kutukebul B. tabaci biotipe B dan non-B pada tanaman cabai. Penelitian dilakukan dengan mengamati perkembangan sejak telur sampai menjadi dewasa di growth chamber yang terkontrol suhu dan pencahayaannya. Pengamatan dilakukan terhadap beberapa aspek biologi dan beberapa parameter statistik demografi. Hasil penelitian menunjukkan bahwa kutukebul B. tabaci biotipe B memiliki beberapa aspek biologi yang berbeda dengan non-B pada tanaman cabai. Siklus hidup kutukebul B. tabaci biotipe B dan non-B masing-masing adalah 33,27 dan 30,86 hari. Kutukebul B. tabaci biotipe B memiliki laju reproduksi bersih (R0) yang hampir sama dengan biotipe non-B, begitu juga rataan masa generasinya. Namun demikian, laju pertambahan intrinsik (r) kutukebul B. tabaci biotipe B 2,5 kali lebih cepat dibandingkan biotipe non-B. Kutukebul B. tabaci biotipe B berlipat ganda populasinya (DT) 2 kali lebih cepat dibandingkan biotipe non-B. Kutukebul B. tabaci biotipe B berpotensi lebih berbahaya dibandingkan dengan biotipe non-B sehingga perlu diwaspadai keberadaannya.

The practice of rice crop cultivation will affect the trophic structure and the diversity of insects that are formed. One of the common cultivation practices carried out by farmers was the control of pests by using pesticides. This study aimed to find out which pest management strategies that are effective in maintaining environmental health and understanding how natural enemies were affected by the application of synthetic pesticides. The first treatment was paddy field with integrated pest management (IPM), the second treatment was conventional rice field with a technique of chemical pest management (C-T), while the third treatment was mixed pest management (M-T). Insect sampling was conducted using sweep net, pitfall trap, and direct observation for 10 weeks after planting. Overall, it was found 100 morphospecies, 9 Orders, 56 families, with a total abundance of 6242 individuals per planting season. Based on functional roles it was found 39% as herbivores, 30% as predators, and 14% as parasitoids, 1% pollinators, and 13% decomposers. High insect diversity and abundance were found in the plots using low synthetic pesticides. The C-T control plot had a lower relative abundance of herbivorous insects, parasitoid insects, predators, and decomposers than the other control plots. H' and D index in the Integrated Pest Management (IPM) and Mixed Pest Management (M-T) plots did not show significant differences but differed significantly from the Chemical Control plot (C-T). Therefore, controlling the herbivore insects could apply the pest management based on IPM strategies.

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